Your complete guide to the Regeneron International Science & Engineering Fair

Which Fields Reach the STS Top 40? Our Eleven-Year Dataset of 371 Finalists, 2015-2026

We read eleven editions of the official Regeneron Science Talent Search program books and classified the research field of 371 of roughly 440 top-40 finalists. Over those eleven years Mathematics is the single largest field at 45 finalists (12.1%), with Computational Biology & Bioinformatics second at 39 (10.5%). Before anything else: STS is for U.S. high school seniors only.

Before the numbers: who can actually enter STS

This matters more than any figure below, so it goes first.

The Science Talent Search is for U.S. high school seniors. A student at a school in mainland China cannot enter it; the realistic route there is Regeneron ISEF, reached by winning at a Society-affiliated fair. Students on a U.S. high-school path — including Chinese students studying at U.S. high schools — are the ones for whom STS is in scope. We will not blur that line to make an article feel more relevant than it is.

With that established, here is what the competition actually is, drawn from the program books and societyforscience.org:

  • It has run since 1942 and is a programme of Society for Science. The books describe it as “the nation's oldest and most highly regarded science competition for high school seniors”.
  • Sponsors in order: Westinghouse, then Intel, then Regeneron. Regeneron's commitment is described as ten years and $100 million.
  • There is no qualifying fair. Entry is by direct application: an extensive submission including a written research report plus supporting documentation from schools, advisors and mentors.
  • Evaluators and judges “select 300 scholars and 40 finalists from the entrant pool”. The top 40 attend a finals week in Washington, D.C. and display their research publicly.
  • Every finalist entry is a single-author original research project.
  • In 2026, finalists competed for more than $1.8 million; the total annual distribution is $3.1 million.

Note the structural difference hiding inside those bullets: STS judges a written body of work submitted directly by an individual senior, while ISEF judges a project that has already survived a fair. Two selection machines — and two different ways of naming what a project is about.

How we built this dataset, and the four things it cannot tell you

The whole value of this article is a compilation nobody has published, so you are entitled to the method before the findings.

We worked from the official program books for eleven editions and assigned each finalist's project to a research field, based on how the book itself phrases what the project is about. The classification is ours. These are not Society statistics and must never be quoted as such. We could classify 371 of roughly 440 finalists; per-year coverage runs from 29 of 40 up to a complete 40 of 40. 2019 has no program book in our set and is a gap — there are eleven years of data here, not twelve.

The books are Society for Science copyright, and the Society's Rights & Permissions terms require permission to republish. So this piece contains no finalist write-ups, no project descriptions and no profile text, and no student names. Everything here is our own characterisation at the level of fields and patterns.

Four limits, stated up front rather than buried:

  1. Category share is not a win rate. To compute a win rate you need the denominator — how many students entered in each field — and the entrant pool is unknown to us. A field with 45 finalists may have had many more applicants than a field with 14. We cannot tell you, and neither can anyone else working from the books alone.
  2. The labels are judgement calls. A protein-structure prediction project could sit under computational biology, computer science or cell and molecular biology depending on which sentence you weight. We were consistent; a different reader would still move some projects.
  3. Coverage varies, so early years are thinner. 2015 gave us 29 classifiable projects; 2025 and 2026 gave us 40. Any apparent broadening of the field over time is partly this.
  4. This is the top 40 only. It says nothing about the 300 scholars, and nothing about the shape of the applicant pool below them.

The eleven-year picture: twelve fields, 328 of 371 finalists

Here is the aggregate. The twelve largest fields account for 328 of the 371 classified finalists — 88.4% — with the remaining 43 spread across smaller fields including neuroscience, space science, plant sciences and genomics, each of which does appear in individual years further down this page.

Field (our classification) Finalists, 2015–2026 Share of 371
Mathematics 45 12.1%
Computational Biology & Bioinformatics 39 10.5%
Engineering 34 9.2%
Medicine & Health 32 8.6%
Cell & Molecular Biology 31 8.4%
Chemistry 29 7.8%
Computer Science 28 7.5%
Environmental Science 23 6.2%
Physics 19 5.1%
Animal Sciences 17 4.6%
Behavioural & Social Sciences 17 4.6%
Materials Science 14 3.8%
Our own compilation from eleven official Regeneron STS program books, covering 371 of roughly 440 finalists. Not Society statistics. 2019 is absent from our set.
Horizontal bar chart of the twelve largest research fields among 371 classified Regeneron STS finalists from 2015 to 2026. Mathematics 45, 12.1 percent. Computational Biology and Bioinformatics 39, 10.5 percent. Engineering 34, 9.2 percent. Medicine and Health 32, 8.6 percent. Cell and Molecular Biology 31, 8.4 percent. Chemistry 29, 7.8 percent. Computer Science 28, 7.5 percent. Environmental Science 23, 6.2 percent. Physics 19, 5.1 percent. Animal Sciences 17, 4.6 percent. Behavioural and Social Sciences 17, 4.6 percent. Materials Science 14, 3.8 percent.
The eleven-year aggregate. Mathematics leads, but read the caveat on the bottom line before you read anything into that.

Year by year, with coverage shown honestly

The table below lists, for each edition, how many of the 40 finalists we could classify and every field with two or more classified finalists that year, in order. Fields with a single finalist in a given year fall below that listing threshold and do not appear — which is why the columns will not sum to the eleven-year totals above. The aggregate counts include those single appearances; the year rows do not.

Year Classified Fields with two or more classified finalists
2015 29 / 40 Mathematics 5; Engineering 4; Chemistry 4; Plant Sciences 2; Animal Sciences 2; Comp. Bio & Bioinformatics 2; Computer Science 2; Physics 2; Materials Science 2
2016 29 / 40 Engineering 5; Comp. Bio & Bioinformatics 3; Cell & Molecular Biology 3; Materials Science 3; Mathematics 3; Physics 3; Environmental Science 2; Computer Science 2; Medicine & Health 2
2017 30 / 40 Medicine & Health 6; Mathematics 5; Cell & Molecular Biology 3; Chemistry 3; Engineering 3; Comp. Bio & Bioinformatics 3; Behavioural & Social Sciences 2; Space Science 2
2018 32 / 40 Mathematics 6; Cell & Molecular Biology 5; Chemistry 4; Computer Science 4; Physics 3; Engineering 3; Plant Sciences 2; Genomics 2
2019 No program book in our set. This year is a gap in the dataset.
2020 32 / 40 Comp. Bio & Bioinformatics 5; Environmental Science 5; Mathematics 4; Cell & Molecular Biology 3; Engineering 3; Medicine & Health 2; Plant Sciences 2; Animal Sciences 2
2021 34 / 40 Comp. Bio & Bioinformatics 5; Medicine & Health 5; Mathematics 5; Cell & Molecular Biology 3; Chemistry 3; Engineering 3; Materials Science 2; Environmental Science 2; Physics 2; Neuroscience 2
2022 37 / 40 Comp. Bio & Bioinformatics 6; Behavioural & Social Sciences 5; Engineering 5; Environmental Science 5; Computer Science 4; Mathematics 3; Physics 2; Animal Sciences 2
2023 30 / 40 Chemistry 4; Mathematics 4; Cell & Molecular Biology 4; Environmental Science 3; Neuroscience 3; Computer Science 3; Comp. Bio & Bioinformatics 2; Medicine & Health 2
2024 38 / 40 Cell & Molecular Biology 5; Medicine & Health 4; Engineering 4; Neuroscience 4; Computer Science 3; Mathematics 3; Comp. Bio & Bioinformatics 3; Environmental Science 2; Space Science 2; Materials Science 2; Animal Sciences 2; Chemistry 2
2025 40 / 40 Medicine & Health 4; Comp. Bio & Bioinformatics 4; Animal Sciences 4; Computer Science 3; Chemistry 3; Cell & Molecular Biology 3; Mathematics 3; Space Science 3; Materials Science 2; Neuroscience 2; Behavioural & Social Sciences 2; Physics 2; Environmental Science 2; Engineering 2
2026 40 / 40 Comp. Bio & Bioinformatics 5; Computer Science 5; Mathematics 4; Medicine & Health 4; Space Science 3; Animal Sciences 3; Chemistry 3; Behavioural & Social Sciences 2; Materials Science 2; Physics 2; Neuroscience 2; Engineering 2; Cell & Molecular Biology 2
Year-by-year breakdown from our own compilation. Coverage improves over the period, so later years show more fields clearing the two-finalist threshold — treat any “broadening” with that in mind.

Two things stand out. First, Mathematics is the only field appearing in every one of the eleven year rows, and never below three — never spectacular, its high being six in 2018, but never absent. That is what a sustained pipeline looks like. Second, no field owns the competition: even the largest is roughly one in eight.

The computational turn is real, and it is not what people assume

The clearest movement in eleven years is Computational Biology & Bioinformatics. It sat outside the top four in both 2015 and 2018. It then finished first or joint-first in 2020, 2021, 2022 and 2026 — four of the last seven editions in our set.

Two-row grid comparing classified finalist counts by year for Mathematics and for Computational Biology and Bioinformatics. Mathematics: 2015 five, 2016 three, 2017 five, 2018 six, 2019 no book, 2020 four, 2021 five, 2022 three, 2023 four, 2024 three, 2025 three, 2026 four. Computational Biology and Bioinformatics: 2015 two, 2016 three, 2017 three, 2018 fewer than two, 2019 no book, 2020 five, 2021 five, 2022 six, 2023 two, 2024 three, 2025 four, 2026 five. The years 2020, 2021, 2022 and 2026 are highlighted as first or joint-first.
Mathematics holds a floor of three in every year we could read. Computational biology climbs from the lower half of the 2015 table to first or joint-first in four editions.

Now the part that is routinely misread. Computational method spread into biology and medicine; it did not replace them. Cell & Molecular Biology totals 31 over eleven years and led the 2024 table with five. Medicine & Health totals 32 and sat joint-top in 2025 with four. Neither collapsed. What changed is that biological questions answered with computational tools became numerous enough to form their own visible block.

That is a claim about method, not about subject. A student reading this as “stop doing biology, start doing code” has drawn precisely the wrong conclusion. The defensible reading is: an increasing share of strong senior-year research now involves substantial computation, wherever the question comes from — and being unable to handle data is becoming a limit on what questions you can attempt.

What this does and does not tell you — and how ISEF differs

Let us be blunt about the misuse this data invites.

It does not say “pick mathematics to win”. Forty-five finalists over eleven years tells you how many mathematics projects reached the top 40; it tells you nothing about how many were submitted. If mathematics also attracts the most entrants, its finalist share could reflect a lower success rate than a smaller field. We cannot compute that and neither can you, from these books. Anyone who quotes a “best category” from finalist counts alone is doing arithmetic without a denominator.

What it does say is which fields sustain a pipeline — which ones produce work at this level year after year rather than in one lucky cohort. Mathematics, computational biology, engineering, medicine, cell and molecular biology and chemistry all clear 29 finalists across the period. Those are fields where a senior working alone can reach a defensible original result — useful to know at fifteen or sixteen, when the real question is whether your interest can produce a completable project at all.

Finally, the contrast with ISEF, because the two are constantly conflated.

Science Talent Search Regeneron ISEF
Who may enter U.S. high school seniors Grades 9–12, individual or a team of up to three
How you get in Direct application — no qualifying fair By winning at a Society-affiliated local, regional, state or national fair
Scale 300 scholars and 40 finalists from the entrant pool More than 1,700 finalists in 2026, from 365 affiliate fairs in more than 60 countries, regions and territories
Fields No fixed category list used here — the twelve fields above are our labels Finalists compete across 22 different scientific categories defined by the Society
Running since 1942 1950
Sources: the STS program books and societyforscience.org, checked 5 August 2026. The field labels on the STS side are ours; the 22 ISEF categories are the Society's.

The practical consequence: do not map our twelve STS fields onto ISEF's 22 categories. They are different taxonomies applied to different, differently-selected populations, and ISEF's field is more than forty times larger at the finals stage. If you are entering ISEF, work from the Society's own definitions — we walk through all of them in our guide to the 22 ISEF categories, and the structure of the competition itself is covered in what ISEF is and how ISEF works. The 2026 fair ran 9–15 May in Phoenix. We are separately told the 2027 fair returns to Los Angeles in May 2027; that comes through our own organisation's channels rather than a Society announcement, so confirm it on societyforscience.org before you plan around it.

The most useful signal in eleven years of books is not which field wins. It is that a single student, working alone, can reach a displayable result in fields as different as pure mathematics and animal sciences. The field is not the constraint. The question is.

Frequently asked questions

Can a student in mainland China enter the Science Talent Search?
No. STS is for U.S. high school seniors. The realistic route is ISEF, qualified through a Society-affiliated fair.

Does Mathematics leading at 12.1% mean it is the easiest category to win?
No. Finalist share is not a win rate. The number of entrants per field is unknown to us, so no success rate can be computed.

Are these official Society for Science statistics?
No. They are our own classification of 371 of roughly 440 finalists, based on how each program book phrases the project's field.

Why is 2019 missing from the dataset?
We have no 2019 program book in our set. That edition is a gap, so this is eleven years of data, not twelve.

This is an independent guide operated by Hanlin Education for China-based international-school students. We are not affiliated with, endorsed by, or sponsored by the Society for Science, the Regeneron Science Talent Search or Regeneron ISEF. The finalist-field figures on this page are our own compilation from the official program books and are not Society statistics; the books themselves remain Society for Science copyright and are not reproduced here. Confirm current rules, eligibility and dates on societyforscience.org. Errors are corrected within 7 working days.